On August 7, Habib Daoud, a Lebanese professor of history in Iran, was gunned down on a street in northern Tehran. Killed alongside him was his 27-year-old daughter Maryam. The assassin was riding a motorbike, and escaped without being identified.   Reports suggest that Daoud’s killing was carried out by Israeli spies. It fits the profile of those carried out by Israeli agents in Iran in previous years. Past targets, however, were mainly Iranian nuclear scientists. Daoud was a different kind of enemy to Israel. He was said to be affiliated with the Lebanese militant group Hezbollah, which is funded by Iran. At least, that was the story reported by the Iranian press.   Thre months later, news reports in the United States and Saudi Arabia told a different story, in which the man Iranian authorities identified as Habib Daoud never actually existed. While the assassins were still likely to be Israeli agents, Daoud’s identity was a cover.   There is a strong likelihood, rather, that the man assassinated in Tehran that day was a senior operative in one of the world’s most notorious terrorist organisations – one that has long claimed to be an enemy of Iran’s government.   The man has been identified by US and Israeli officials as Abu Muhammad Al Masri, second-in-command of Al Qaeda.   On this week's Beyond the Headlines host Sulaiman Hakemy looks at Iran’s covert and counterintuitive relationship with Al Qaeda.